The present invention relates to an improved multilayer head core and a method for manufacturing the same, and more particularly relates to improvements in a multilayer head core used for magnetic heads in magnetic sound recording and reproducing devices, magnetic video recording and reproducing devices, and the like, and in a method for manufacturing same.
It is in general required for the magnetic material for head cores to have high magnetic permeability and high abrasion resistance accompanied by reduced eddy current loss in the high frequency of the electric current.
However, relatively high permeability of such material leads to increased eddy current loss in the high frequency range when such material is used for head cores, while resulting in lower effective permeability.
In order to avoid such lowering in effective permeability, it is proposed to superimpose a plurality of thin layers of the magnetic material such as permalloy and a plurality of insulating material layers alternately to each other to obtain multilayer head cores. For this purpose, the conventional magnetic alloy material such as permalloy is first subjected to cold working to produce thin layers of head core shape, and a plurality of such thin layers are bonded together by adhesive with insulating material layers interposed therebetween to obtain a head core structure.
Recently, the performance requirements for the head core have become more stringent, and new magnetic alloy materials such as sendust and alperm alloys are spotlighted in the possible use to the head cores. These new alloys, indeed, have excellent characteristics as magnetic head core materials, but low workability of these alloys makes it very difficult to work the material alloys into thin layers with low manufacturing cost.